The assignee of the present invention has proposed a parallel/serial data link in which a transmitter having two ports is connected via two optical fibers to a receiver having two ports. For convenience, the two transmitter ports will be referred to as transmitter ports A and B and the two receiver ports will be referred to as receiver ports A and B. The optical fiber connected to transmitter port A will be referred to as fiber A and the optical fiber connected to transmitter port B will be referred to as fiber B.
Unless special precautions are taken, fiber A may be connected to either one of receiver ports A and B. Similarly, fiber B may be connected to either one of receiver ports A and B. In such a case, if receiver port B is connected to transmitter port A (or if receiver port A is connected to transmitter port B), the receiver will fail to properly process data received from the transmitter.
According to known techniques, keying systems may be employed to assure that transmitter port A is connected via fiber A to receiver port A and transmitter port B is connected via fiber B to receiver port B. However, such keying systems increase the cost of the optical fibers and the transmitter and receiver ports by requiring special parts and processing. Optical fibers also may be labeled or physically marked to facilitate proper connection. However, even with labeling, the optical fibers may be connected improperly. In such instances, a user typically will be unaware of this misconnection, resulting in confusion and/or system downtime. Accordingly, other techniques for assuring the proper connection of transmitter port A and receiver port A, and transmitter port B and receiver port B, would be desirable.